The present invention relates to non-sticking composite materials for office automation equipment which are produced by applying, to a substrate, a fluorine-containing polymer excellent in non-sticking property, stain-proofing property, abrasion resistance, heat resistance and elasticity and particularly in adhesive property to the substrate.
In the present invention, the office automation equipment means a whole electronic business machine and its peripheral devices intended for enhancing efficiency and quality of office work, and particularly means electronic equipment such as copying machine, printer, facsimile machine, personal computer and multifunctional phone which make the best use of information processing technology.
Hitherto with respect to so-called office automation equipment (hereinafter simply referred to as xe2x80x9cOA equipmentxe2x80x9d) such as facsimile machine and copying machine, various materials have been used on surfaces of parts of OA equipment, for example, a fuser roller having a function to fix a toner powder electrostatically sticking on a paper by heat and pressure, a charging roller having a function to give a given amount of electrostatic charge to a surface of a photosensitive drum by using a high voltage power source, a transfer roller or transfer belt having a function to give an electrostatic charge to a paper from a high voltage power source and transfer a toner powder electrostatically sticking on a surface of a photosensitive drum to the paper and other parts to enable those parts to fully exhibit their functions.
The above-mentioned charging roller is produced by applying a chloroprene rubber or epichlorohydrin rubber to a urethane rubber substrate and thereon nylon in the form of tube which was subjected to treating with a conductivity imparting agent for adjusting conductivity and resistance from the viewpoint of imparting and regulating conductivity, making resistance uniform and making separation of paper easy. Alternatively the charging roller is used as it is without applying anything to the above-mentioned substrate. However there is a problem that a surface of the obtained roller is poor in abrasion resistance, non-sticking property against toner and paper feeding property.
Also in cases of the above-mentioned fuser roller and pressure roller, from the viewpoint of non-sticking property against toner, separation of a copying paper, elasticity and abrasion resistance, the following application methods can be considered, that is, {circle around (1)} a method of applying, to a metallic substrate, a tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA) in the form of tube or coating, {circle around (2)} a method of applying, to a metallic substrate, a silicon rubber, fluorine-containing rubber and silicon rubber in that order and applying a silicon oil or fluorine-containing silicon oil to an outermost layer, and {circle around (3)} a method of applying, to a metallic substrate, a silicon rubber or fluorine-containing rubber or further PFA in the form of tube. Thus a fluorine-containing polymer having excellent characteristics such as abrasion resistance and non-sticking property is applied to surfaces of parts of various OA equipment. However due to its excellent non-sticking property, there are problems that the fluorine-containing polymer is insufficient in adhesion to a substrate such as metal, glass or resin (excluding a fluorine-containing polymer) of the above-mentioned parts of OA equipment and causes poor processability in producing the parts and lower abrasion resistance during use, and further that non-sticking property which a fluorine-containing polymer possesses inherently is not enough against a toner and paper feeding ability is not good. Thus those problems become obstruction against an increase in operation speed of various OA equipment and enhancement of durability required therefor which comply with demands for high quality picture, coloring and increase in information processing speed as performance of OA equipment becomes high in highly developed information-intensive society of these days.
Therefore to compensate for lack of adhesion of a fluorine-containing resin, in case where the fluorine-containing polymer is used in the form of coating, there is a method of adhering a fluorine-containing resin to a substrate by roughening the surface of metal chemically or physically with expecting anchor effect between them. However this method requires much labor in the surface roughening itself, and though initial adhesion is possible, lowering of the anchor effect arises when a temperature change is made repeatedly and in case of use at high temperature.
Also a method for chemically activating a surface of a fluorine-containing resin by treating the surface with a solution prepared by dissolving metallic sodium in liquid ammonia has been proposed. However in that method, not only there is a fear that the solution itself causes environmental pollution but also there is a problem that its handling is attended with danger.
Further though a method for carrying out physical and chemical treatment such as plasma sputtering on a surface of a fluorine-containing resin has been proposed for activation of the resin surface, there is a problem that much labor is required for the treatment and an increase in cost is resulted.
Also in order to improve adhesion of a fluorine-containing resin coating, investigations with respect to addition of various components and formation of a primer layer have been made.
For example, there is a technique of adding an inorganic acid such as chromic acid to a coating composition containing a fluorine-containing resin to form chemical conversion coating film on a surface of metal for enhancing adhesion of the composition (JP-B-63-2675). However since chromic acid contains hexahydric chromium, it cannot be said that such a technique is sufficient in view of safety in food and coating work. Further in case of use of other inorganic acids such as phosphoric acid, there was a problem that safety of a fluorine-containing resin coating composition is damaged.
Use of a coating composition containing a fluorine-containing resin as a primer, in which heat resistant resins such as polyamide imide, polyimide, polyethersulfone and polyether ether ketone and in addition, a metal powder are added instead of the above-mentioned inorganic acid, has been studied (JP-A-6-264000). Inherently there is almost no compatibility between a fluorine-containing resin and a heat resistant resin. Therefore there arises a phase separation in a coating film, thus easily causing intercoat adhesion failure between the primer and the top coat of the fluorine-containing resin. Further film defects such as pin holes and cracks arise easily at the time of processing at high temperature or during use due to a difference in heat shrinkage between the fluorine-containing resin and the heat resistant resin or due to lowering of elongation of the coating film by the addition of the heat resistant resin. Also since those heat resistant resins are colored brown by baking, property for exhibiting clear surface pattern is poor and it is difficult to use them for applications requiring white and vivid colors and transparency. Further when the heat resistant resin is blended, non-sticking property and friction resistance which the fluorine-containing resin inherently possesses are lowered.
Also for adhesion of a fluorine-containing resin coating composition to a glass, etc. requiring transparency, an improvement of the adhesion has been tried by treating the substrate with a silane coupling agent or adding a silicone resin to the fluorine-containing resin coating composition (JP-B-54-42366, JP-A-5-177768). However enhancement of adhesion is insufficient, heat resistance is lowered and separation of a coating film, foaming and coloring arise easily at sintering or in use at high temperature.
On the contrary, fluorine-containing resin coating compositions prepared by copolymerizing a hydrocarbon monomer (containing no fluorine) containing functional group such as hydroxyl or carboxyl have been discussed. However since those coating compositions were originally studied mainly for a purpose of weather resistance, it is difficult to use them for application requiring heat resistance for 200xc2x0 to 350xc2x0 C. and for applications requiring non-sticking property and friction resistance.
Namely with respect to a polymer prepared by copolymerizing a hydrocarbon monomer (containing no fluorine) having functional group, thermal decomposition easily occurs on components of the monomer at the time of processing at high temperature or during use, and thus coating film failure, coloring, foaming, separation, etc. arise, which makes it impossible to attain purposes of coating a fluorine-containing resin.
Further fluorine-containing resins are generally insufficient in mechanical strength and dimensional stability, and high in price. In order to minimize those disadvantages and make the best use of the above-mentioned merits which the fluorine-containing polymer possesses inherently, investigations have been made also with respect to its use in the form of film.
However the fluorine-containing resin inherently has low adhesive force, and it is difficult to adhere the fluorine-containing polymer in the form of a film directly to other material (substrate). For example, even if the adhering is tried by thermo-processing, adhesive strength of the fluorine-containing polymer is not enough, or even if the polymer has adhesive force to a certain extent, such an adhesive force is apt to vary depending on kind of the substrate. Thus in many cases, reliability on the adhesive strength of the fluorine-containing polymer has been not so enough.
In order to adhere the fluorine-containing resin film to a substrate, mainly the following methods have been studied:
1. a method for physically roughening a surface of substrate by sand blasting, etc.,
2. a method for surface-treating a fluorine-containing resin film by chemical treatment such as sodium etching, plasma treatment, photochemical treatment, etc.,
3. a method for adhering by using an adhesive, and other methods. With respect to the methods 1 and 2 above, surface-treating steps are required, and the steps are complicated and productivity is poor. Also kinds and shapes of substrates are restricted. Further the obtained adhesive force is insufficient, and also there easily occur a problem with appearance (property for exhibiting clear surface pattern) of the obtained composite materials such as coloring and color. Also the method of using a chemical such as sodium etching has a problem with safety.
Use of an adhesive in the method 3 above has also been discussed. A usual hydrocarbon type (containing no fluorine) adhesive does not have enough adhesive property and its heat resistance is insufficient. Thus a hydrocarbon type adhesive cannot stand under conditions for adhering of a fluorine-containing polymer film which requires molding and processing at high temperature, and peeling due to decomposition of the adhesive and coloring occur. Since an adhesive layer of the above-mentioned laminated article produced by using an adhesive also is insufficient in heat resistance, chemical resistance and water resistance, it cannot maintain adhesive force due to a change in temperature and environment, and lacks in reliability.
On the contrary, adhesion by using an adhesive composition comprising a fluorine-containing polymer having functional group is discussed.
For example, it is reported that a fluorine-containing polymer prepared by graft-polymerizing, to the fluorine-containing polymer, a hydrocarbon monomer which has carboxyl represented by maleic anhydride and vinyltrimethoxysilane, a residual group of carbonic acid, epoxy or a hydrolyzable silyl group, is used as an adhesive (for example, JP-A-7-18035, JP-A-7-25952, JP-A-7-25954, JP-A-7-173230, JP-A-7-173446, JP-A-7-173447) and that an adhesive composition comprising a fluorine-containing copolymer prepared by copolymerizing a hydrocarbon monomer having functional group such as hydroxyalkyl vinyl ether with tetrafluoroethylene or chlorotrifluoroethylene and an isocyanate hardening agent is cured and used as an adhesive between vinyl chloride resin and corona-discharged ETFE (for example, JP-A-7-228848).
The above-mentioned adhesive composition comprising a fluorine-containing resin prepared by graft-polymerizing or copolymerizing a hydrocarbon monomer having functional group does not have enough heat resistance, and thus at the time of processing a composite material comprising the adhesive composition and a fluorine-containing resin film at high temperature or during use at high temperature, decomposition and foaming occur, thereby causing reduction of adhesive strength, peeling and coloring. In case of the adhesive composition disclosed in JP-A-7-228848, it is necessary to corona-discharge the fluorine-containing resin film.
As mentioned above, no non-sticking composite materials for parts of OA equipment which meet all the above-mentioned requirements and assure strong adhesion to a substrate have been obtained.
In view of the above-mentioned facts, an object of the present invention is to provide non-sticking composite materials for OA equipment which are produced by applying, to a substrate, a material comprising a fluorine-containing polymer being excellent in adhesion to the substrate without necessitating complicated steps and can be used for various parts of OA equipment.
Further an object of the present invention is to obtain the non-sticking composite materials for OA equipment excellent in non-sticking property, abrasion resistance, durability, elasticity, stain-proofing property and sliding property.
The present invention relates to non-sticking composite materials for office automation equipment which are produced by applying, to a substrate, a material comprising a fluorine-containing ethylenic polymer having functional group and prepared by copolymerizing:
(a) 0.05 to 30% by mole of at least one of fluorine-containing ethylenic monomers having at least one functional group selected from the group consisting of hydroxyl, carboxyl, a carboxylic salt group, a carboxylic ester group and epoxy and
(b) 70 to 99.95% by mole of at least one of fluorine-containing ethylenic monomers having no functional group mentioned above.
In that case, it is preferable that the above-mentioned fluorine-containing ethylenic monomer (a) having functional group is at least one of fluorine-containing ethylenic monomers represented by the formula (1):
xe2x80x83CX2=CX1xe2x80x94Rfxe2x80x94Yxe2x80x83xe2x80x83(1)
wherein Y is xe2x80x94CH2OH, xe2x80x94COOH, a carboxylic salt group, a carboxylic ester group or epoxy, X and X1 are the same or different and each is hydrogen atom or fluorine atom, Rf is a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms, a fluorine-containing oxyalkylene group having 1 to 40 carbon atoms, a fluorine-containing alkylene group having ether bond and 1 to 40 carbon atoms or a fluorine-containing oxyalkylene group having ether bond and 1 to 40 carbon atoms.
Further it is preferable that the fluorine-containing ethylenic monomer (b) having no functional group mentioned above is tetrafluoroethylene.
Further it is preferable that the fluorine-containing ethylenic monomer (b) having no functional group mentioned above is a monomer mixture of 85 to 99.7% by mole of tetrafluoroethylene and 0.3 to 15% by mole of a monomer represented by the formula (2):
CF2=CFxe2x80x94Rf1xe2x80x83xe2x80x83(2)
wherein Rf1 is CF3 or ORf2, in which Rf2 is a perfluoroalkyl group having 1 to 5 carbon atoms.
Further it is preferable that the fluorine-containing ethylenic monomer (b) having no functional group mentioned above is a monomer mixture comprising 40 to 80% by mole of tetrafluoroethylene, 20 to 60% by mole of ethylene and 0 to 15% by mole of other monomer copolymerizable with those monomers.
In the present invention, it is also preferable that the fluorine-containing ethylenic polymer having functional group is prepared by copolymerizing:
(a) 0.01 to 30% by mole of the fluorine-containing ethylenic monomer having functional group with
(b) 99.95 to 70% by mole of a monomer mixture comprising 40 to 90% by mole of vinylidene fluoride, 0 to 30% by mole of tetrafluoroethylene and 10 to 50% by mole of hexafluoropropene on the basis of a total amount of monomers excluding the monomer (a),
a monomer mixture comprising 40 to 70% by mole of tetrafluoroethylene, 30 to 60% by mole of propylene and 0 to 20% by mole of other monomer copolymerizable therewith on the basis of a total amount of monomers excluding the monomer (a) or
a monomer mixture comprising 40 to 85% by mole of tetrafluoroethylene and 15 to 60% by mole of perfluoro(vinyl ether) on the basis of a total amount of monomers excluding the monomer (a).
In the present invention, it is preferable that the fluorine-containing ethylenic polymer having functional group is applied to a substrate in the form of a coating composition.
Further it is preferable that the fluorine-containing ethylenic polymer having functional group is applied to a substrate in the form of a film.
It is preferable that the substrate is a metallic substrate.
It is preferable that the substrate is a synthetic resin substrate.
It is preferable that the substrate is a glass substrate.
It is preferable that the substrate is a metallic substrate comprising an aluminum-based metal.
It is preferable that the substrate is a metallic substrate and the above-mentioned material is applied with a layer of elastic member being inserted between the substrate and the material.
It is preferable that the layer of elastic member comprises a silicone rubber.
Also it is preferable that the layer of elastic member comprises a fluorine-containing rubber.
It is preferable that the synthetic resin substrate is made of polyimide.
Also it is preferable that the synthetic resin substrate is made of a heat resisting thermoplastic resin.
It is preferable that the heat resisting thermoplastic resin is polyphenylene sulfide.
Also it is preferable that the heat resisting thermoplastic resin is polyamide imide.
Also it is preferable that the heat resisting thermoplastic resin is polyetherimide.
The present invention relates to rollers for office automation equipment which are produced by using the above-mentioned non-sticking composite materials for office automation equipment.
In that case, it is preferable that the fluorine-containing ethylenic polymer having functional group is applied to a substrate in the form of a coating composition.
Further it is preferable that the fluorine-containing ethylenic polymer having functional group is applied to a substrate in the form of a tube.
Further the present invention relates to a fuser roller produced by using the non-sticking composite materials for office automation equipment.
Further the present invention relates to a pressure roller produced by using the non-sticking composite materials for office automation equipment.
Further the present invention relates to a charging roller produced by using the non-sticking composite materials for office automation equipment.
The present invention relates to a transfer roller produced by using the non-sticking composite materials for office automation equipment.
The present invention relates to belts for office automation equipment which are produced by using the non-sticking composite materials for office automation equipment.
The present invention relates to belts for office automation equipment which are produced by using the non-sticking composite materials for office automation equipment, in which the fluorine-containing ethylenic polymer having functional group is applied to a substrate in the form of a coating composition.
The present invention relates to belts for office automation equipment which are produced by using the non-sticking composite materials for office automation equipment, in which the fluorine-containing ethylenic polymer having functional group is applied to a substrate in the form of a film.
The present invention relates to belts for office automation equipment which are produced by using the non-sticking composite materials for office automation equipment.
The present invention relates to a transfer belt produced by using the non-sticking composite materials for office automation equipment.
The present invention relates to sliding parts for office automation equipment which are produced by using the non-sticking composite materials for office automation equipment.
The present invention relates to sliding parts for office automation equipment which are produced by using the non-sticking composite materials for office automation equipment, in which the fluorine-containing ethylenic polymer having functional group is applied to a substrate in the form of a coating composition.
The present invention relates to sliding parts for office automation equipment which are produced by using the non-sticking composite materials for office automation equipment, in which the fluorine-containing ethylenic polymer having functional group is applied to a substrate in the form of a film.
In those cases, it is preferable that the substrate is made of polyphenylene sulfide, polyamide imide or polyetherimide.
Also the present invention relates to a separating claw produced by using the non-sticking composite materials for office automation equipment.
Also the present invention relates to a fixing bearing produced by using the non-sticking composite materials for office automation equipment.
Also the present invention relates to a paper delivery roller produced by using the non-sticking composite materials for office automation equipment.
Also the present invention relates to a paper delivery guide produced by using the non-sticking composite materials for office automation equipment.